Broadknife



Feb. 26, 1963 R. G. AMES BROADKNIFE Filed Oct. 24. 1960 INVENTOR.

ROBERT (3. AMES AT TORNEYS lllllll 3,978,49l Fatented Feb. 25, 19533,073,491 BROADKNIFE Robert G. Ames, Hilisborough, Calif., assignor, bymesne ass gnments, to Arms Taping Tool Systems Manufactuning Co.,Harvey, lill., a chrporation of Delaware Filed Oct. 24, 1960, Ser. No.64,572 1 Claim. (Cl. 15236) The present invention relates toimprovements in a broadknife. It consists of the combinations,constructions, and arrangement of parts, as hereinafter described andclaimed.

An object of my invention is to provide a broadknife having a resilienttrowelling blade which is connected to an operating handle, the bladebeing reinforced by resilient shims positioned to reduce the bendingpressure on the area where the handle is connected to the blade, whenthe blade is flexed, and to distribute the bending pressure over a widerarea. This arrangement will prevent breakage of the blade as the latteris flexed.

Other objects and advantages will appear as the specification proceeds.The novel features will be set forth in the appended claim.

Drawing For a better understanding of the invention, reference should behad to the accompanying drawing, forming part of this specification, inwhich:

k l flGURE 1 is a fragmentary plan view of my broad- 'm e;

FIGURE 2 is a side elevational view thereof; and

FIGURE 3 is a plan view of one of the resilient shims.

While I have shown only the preferred form of my invention, it should beunderstood that various changes, or modifications, may be made withinthe scope of the annexed claim without departing from the spiritthereof.

Detailed Description In carrying my invention into practice, I provide ahandle indicated generally at A, which is fashioned with a bifurcatedend B defining a pair of spaced lugs arranged in confronting relationwith one another. The handle A may be made of any suitable length and ispreferably made of tubular material having a bore 11 extendinglongitudinally thereof. The bifurcation in the bandie defines saddles 12on opposite lateral sides of the handle.

Moreover, I provide a resilient trowelling blade C having opposite faces13, a leading end 14 and a trailing end 15, the latter providing atrowelling edge when the broadknife is being used. The spaced lugs 10are disposed to straddle the leading end 14 of the blade C, when thebroadknife is assembled. It will be apparent that the blade C defines atrowelling portion C extending rearwardly beyond the lugs 10.

As clearly shown in the drawing, a pair of resilient reinforcing shims Dproject into the space between the lugs 1%, with each shim beinginterposed between one of the lugs 10 and the adjacent face 13 of theblade. Bolts 16 are inserted through holes 17 formed in the lugs 1t),and these bolts extend through holes 18 in the shims D and holes 19 inthe blade C. These bolts are provided with nuts 29 for drawing the lugs10 into clamping relation with the interposed blade C and shims D,thereby removably connecting the blade C to the handle A.

Referring to FIGURE 1, it will be observed that the shims D projectlongitudinally beyond the lugs 10 toward the trailing end of the bladeC; and, also, project laterally in both directions beyond the lugs. Theshims D bear against the opposite faces 13 of the blade C to therebyreduce the bending pressure on the area where M the lugs it areconnected to the blade, when the blade is flexed, and the shimsdistribute the bending pressure over a wider area for preventingbreakage of the blade.

Particular attention is called to the fact that the blade C is fashionedwith opposite lateral side edges 21 that converge toward the leading end14 thereof. These edges 21 project into the bore 11 of the handle A andare seated in the saddles 12, thereby aiding in supporting the bladeagainst lateral displacement from between the lugs 19. Moreover, eachshim D is fashioned with opposite lateral side edge portions 22 thatproject into the bore 11 of the handle A and are seated in the saddles12, thus aiding in supporting the shims against lateral displacementfrom between'the lugs 10.

Prior to using the resilient shims D, actual tests disclosed that theblade C would not last very long due to breakage of the blade in thearea where the handle A is connected to the blade. However, when theshims are utilized, the breakage of the blade is at a minimum.

It will be noted that each shim D is formed with opposite lateral sideedges 23 that converge rearwardly relative to one another in a directionextending toward the trailing end 15 of the blade C. When the shims Dare not provided, the normal tendency of the blade is to flex about astress line 24, as the trailing end 15 is pressed against a wall or thelike. It will be apparent from FIGURE 1 that the rearwardly convergingside edges 23 of the shims D are spaced inwardly from the forwardlyconverging lateral side edges 21 of the blade C, and this arrangementwill allow the flexing stress imparted to the blade during use to spreadinto the areas 25 of the blade, which areas are disposed on oppositelateral sides of the shims. This will materially reduce the tendency ofthe blade to break during flexing thereof. Moreover, the rearwardlyconverging side edges 23 extend diagonally relative to the normal stressline 24, and this is an important structural feature contributing to alonger life of the blade.

I claim:

A handle to tool connection comprising a handle having a bore extendinglongitudinally thereof, said handle terminating in a bifurcated endembodying a pair of flat spaced lugs arranged in confronting relationwith one another and projecting beyond the bore end of the handle, thepoints of merger of the sides of said lugs with the bore end of thehandle providing a pair of saddles; a resilient trowelling blade havingopposite faces, leading and trailing ends with the leading end shorterin length than the trailing end and being disposed between the lugs andhaving a non-circular periphery received in the saddles; the bladedefining a trowelling portion extending rearwardly beyond the lugs andof greater width than the width of the lugs; a pair of resilientreinforcing shims projecting into the spaces between the lugs and theadjacent face portions of the blade and having non-circular leadingedges received in the saddles; the shims having trailing edges slightlyless in length than the widths of the ends of the lugs and being spacedfrom the ends of the lugs; said shims also having opposite divergingsides extending from the ends of the shim trailing edges toward thesides of the blade so as to provide lateral shim portions that extendbeyond the sides of the lugs; and connecting means securing the bladeand shims to the lugs.

References Cited in the file of this patent UNITED STATES PATENTS316.924 Visscher Apr. 28, 1885 FOREIGN PATENTS 1,017,961 Germany Oct.17, 1957

